diff --git a/src/resources/extensions/gsd/auto.ts b/src/resources/extensions/gsd/auto.ts
index 325f69286..aadb740d5 100644
--- a/src/resources/extensions/gsd/auto.ts
+++ b/src/resources/extensions/gsd/auto.ts
@@ -475,8 +475,8 @@ export async function startAuto(
 
   // Capture the integration branch — records the branch the user was on when
   // auto-mode started. Slice branches will merge back to this branch instead
-  // of the repo's default (main/master). Idempotent: only writes if not
-  // already recorded, so restarts/resumes don't overwrite.
+  // of the repo's default (main/master). Idempotent when the branch is the
+  // same; updates the record when started from a different branch (#300).
   if (currentMilestoneId) {
     captureIntegrationBranch(base, currentMilestoneId);
     setActiveMilestoneId(base, currentMilestoneId);
diff --git a/src/resources/extensions/gsd/worktree.ts b/src/resources/extensions/gsd/worktree.ts
index ecbfdfffe..4a2c84516 100644
--- a/src/resources/extensions/gsd/worktree.ts
+++ b/src/resources/extensions/gsd/worktree.ts
@@ -55,7 +55,9 @@ export function setActiveMilestoneId(basePath: string, milestoneId: string | nul
 /**
  * Record the current branch as the integration branch for a milestone.
  * Called once when auto-mode starts — captures where slice branches should
- * merge back to. No-op if already recorded or if on a GSD slice branch.
+ * merge back to. No-op if the same branch is already recorded. Updates the
+ * record when the user starts from a different branch (#300). Always a no-op
+ * if on a GSD slice branch.
  */
 export function captureIntegrationBranch(basePath: string, milestoneId: string): void {
   const svc = getService(basePath);